Phonograph



Dec. 31, 1929. RANDHIR slNGH KHAIRA 1,741,465

PHONOGRAPH O Filed Jan. 5, 1928 2 Sheets-Sheet 1 /6 I 71 rver: tor

Dec. SP1, l929. RANDHIR SINGH KHAIRA PHONOGBAPH 2 Sheets-Sheet Filed Jan.

Patented Dec. 31|, 1929 RANDHIR SINGH KHAIRA, F `NAVASOTA, TEXAS' PHONOGRAPH Application -led January 5, 1928. Serial No. 244,668.

The present inventionrelates to improvements in phonographs and has for its principal object to provide an improved turn table and record disc construction whereby the stylus will be .prevented from scratching the record disc after the reproducer carrying'the stylus has traversed the face of the' record disc. Another important object of the invention is to provide a phonograph wherein the record disc is removably supported on the turn table, the securing means being of such construction as to prevent any possibility of the record disc slipping or otherwise moving on l5 the turn table when placed thereon.

A further object is to provide a phonograph wherein the same is electrically operated.

:means being provided for automatically stopping the motor that controls the operation of the turn table carrying armature shaft when the record has been played and the reproducer is disposed within a centrally located cavity former in the face of the record disc.

A still further object is to providel a phonograph of vthe above mentioned character which is simple in construction, inexpensive, 'strong and durable and further Well adapted to the purpose for which it is designed.

Other objects and advantages of the invention will become apparent fromthe following description when taken in connectionwith the accompanying drawings. i

In the accompanying drawings forming part of this application and wherein like reference characters indicate like parts:

' Figure 1 is a sectional view through the turn table and the record disc supported thereon, the phonograph casing being shown of the `operating mechanism for the turn in such a manner as to illustrate the position-A f` ner in which the record disc is the rotatable turn table.

Figure 4 is a top plan view of the turn table.

Figure 5 is a similar view of my improved record disc.

Figure 6 is a detail elevational view of the outer end of the tone arm showing the reproducer supported thereon, and

Figure? is a sectional view taken substantially on the line 7 7 of Figure 6.

In the drawings wherein for the purpose of illustration isshown the preferred embodiment of my invention, the numeral l desig nates the casing, the same having arranged therein an induction motor for any conventional construction and which is designated generally by the numeral 2. The elongated armature shaft 3 that is associated with this motor extends upwardly in the casing, and the upper end extends through a suitable opening provided therefor in the top of the casing as shown more clearly in Figure l. A plate 4 is secured to the bottom face of the top of the casing around the aforementioned opening vfor steadying the armature shaft, and-additional bracing means forl the armature shaft isshown at 5.

Forming a salient part of the present invention is the turn table 6, Athe same being formed with'a central depression or socket -7 in the upper face thereof, as more clearly shown in Figures 3 and 4 of the drawings. Thisturn table is secured on the plate-like head 8 arranged on the upper end of the armature shaft 3 by a screw such as is shown supported on `at 9.A and which screw extends centrally through theturn table. The purpose of the socket or depression 7 will be hereinafter more fully described.

A pair ofdiametrically opposed pins 10 90- extend upwardly-from the upper face ofthe vturn table- 6 adjacent the perimeter thereof, andthe purpose of these pins will also be presently apparent. v

-The invention further'comprehends .the provision of an improved record disc and tolthis end, the disc 11 is provided with an enlarged central hole indicated at 13. The upper and bottom faces of the record disc have formed therein the usual sound grooves 1 14 and the same extend from va point inwardly of the peripheral edge of the disc to the edge of the central hole 13, the sound grooves having communication with the hole as indicated in Figures 2 and 5 of the drawin s.

The peripheral edge portion 15 of the record disc 11 that does not have the sound grooves formed therein is provided at equidistantly spaced points with the openings 16. In the present instance four of such openingsl are provided, Vand these openings cooperate with the upstanding pins for securing the record disc 11 on the turn table so that said disc will not slip or otherwise moveon the turn table when properly positioned thereon. By providing four of such openings 16, itwill be readily obvious that should the record be broken at its edge where one of the openings is formed, the other pair of diametrically opposed openings may e used to permit the securing of the record disc Aon the turn table in a positive manner.

Furthermore, when the record disc is secured on the upper face of the turn table, the central opening 13 that is of the same diameter as the socket or depression 7 will be in alinement with the socket formed in the upper face of the turn table and this is clearly shown in Figures 1 and 3 of the drawings.

The record disc is of smaller diameter than the turn table, and the edge portion of the turn table that extends beyond the outer edge of the record disc is formed with the vnotches 12 as shown in Figure 4 for the purpose of permitting the fingers to easily engage under the adjacent edge portion of the record disc and facilitate the removal of said disc.

Extending upwardly from the top of the casing 1 and adapted for communication with the horn (not shown) that maybe arrangedwithin the casing at any appropriate manner is the throat 17. The lower Jend of this throat is formed with an annular ange 18 that rests on the upper face of the top of the casing in the manner shownvery clearly in Figure 3. This throat is formed with the spaced annular-ribs 19 on the outer face thereof and these ribs cooperate with the annular channels 20 formed in a sleeve 21 that fits over the upper portion of the throat 17 whereby the sleeve is capable of rotation on the throat. The upper end of the sleeve 21 is reduced to form a neck portion-22.

A' tone arm 23 is secured at its inner -end within the neck portion 22 in a rigid manner so that said tone arm will.rotate with the sleeve 21 about the throat 17.

The outer end of the tone arm 23 is disposed laterally as illustrated at 24 and-carried by thisportion of the tone arm is the reproducer'designated generally by the numeral 25, the same being provided with theD sleeve 26 to fit over the laterally extending outer end portion 24 of the-tone arm. This shaped ribs formed on the laterally extending portion 24 of the tone arm.

The sleeve 26 is frictionally engaged with the laterally extending outer end 24 of the tone arm, yet is capable of being turned in an upward and downward direction for facilitating the disposition of the stylus 28 in an operative or inoperative position. A pin and slot arrangement is associated with the laterally extending outer end 24, and the sleeve 26 of the reproducer for lilniting the rotation of the sleeve on the outer end portion of the tone arm, and this pin and slot construction is illustrated at 29 and 30, respectively.

A socket 31 is arranged in the side of the casing and is electricallyT connected to a suitable source of supply by the wires 32 and 33. The motor 2 is electrically connected to the socket by the wiring as shown in Figure 1. For the purpose of starting and stopping the motor, there is provided both a manually operated means as well as anautomatic'vmechanism. The manually controlled mechanism includes the provision of a rheostat 34 within thecasing and cooperating with the rheostat is the manually operable lever 35 that projects beyond the adjacent side of the casing. A contact Velement 36 is associated with this lever for cooperation with the rheostat in t-he manner well known in the art whereby the speed of the motor may be controlled, and furthermore when the lever is in one position, the current to the motor will be cut off.

The automatic mechanism for starting and stopping the motor comprises the provision of an annular ring 37 of any suitable insulating material. This ring encircles the lower portion of the throat 17 and is secured on the flange portion 18 in any appropriate manner. A portion of the insulating ring is cut out and secured within the cut out portion is the segmental contact 38 and adapted for cooperation with this contact is the brush 39 carried by the rotatable sleeve 21 that is associated with the tone arm 23. The brush and segmental contact are electrically' connected to the motor and source of supply by the Wiring shown in Figure 1.

In operation, a record disc of the type shown in Figure 5 is secured on the'turn table 6 and the tone arm is disposed adjacent the outer edge of the disc so that the stylus is in engagement with the outer most record groove 14 formed in the upper face of the record disc. -When the parts are so arranged, the brush 39 will be in engagement with one end of the segmental contact strip 38 and the motor will thus be actuated to elect the r0- ico tation of the turn table and the record discA supported thereon.

When the stylus 28 has completely traversed the upper face of the record disc, and the same reaches the innermost sound groove, by

reason of said innermost sound groove-communicating with the hole in the record, the stylus will enter the hole andthe underlying socket formed in the turn table and thus prem vent the further contact of the stylus with the upper face ofy the record disc. Simultaneously, the brush 39 will have passed beyondv the other end of the contact strip 38 and reach or touch the insulating ring 37 thereby cutting oil the current to the motor, and thus stopping the rotation of the turn table and the record, disc supported thereon.

When the reproducer 25 is disposed in the position shown in Figures lZand 3A of the 2o drawings, the Ostylus cannot contact with the V upper face of the record disc, and therefore the stylus will not be made blunt such as fre- Y quently results when a phonograph of the conventional construction and which employs the usual type of record disc isnot stopped at the proper time. A The provision of a phonograph of theabove y mentioned character will insure the securing of the record disc in a positive manner on the turn table so that there will be no possibility of the record disc slippingor otherwise moving independently of the turn table and thereby the pitch of the notes emitted from the phonograph will in no way be affected. This will permit the phonograph to reproduce the voice in a clear manner. While I have shown the preferred embodiment of my invention, it is to be understood that various changes in the size, shape and arrangement of parts may be resorted to without departing from the spirit of the invention and the scope of the appended claims. 4

Having thus described the invention, what I claim as new and desire to secure by Letters Patent is 1. In a phonograph, the combination of a rotatable turntable havin a central depression formed in the upper ace thereof, and a record discremovably secured on the turn table and having a central hole for receiving the stylus of a phonograph reproducer after the stylus of the reproducer has traversed the record disc..

2. In a phonograph, the combination of a turn table, a record disc providedl with spaced openings in the outeredge portion thereof, and pins extending upwardly from the turn table for disposition through the respective openings for preventing movement of the record disc on the turn table. J 3. In combination, a phonograph turn table, a record disc provided with spaced openings in the outer edge portion thereof, 5 upstanding pins carried by the *um fable for disposition through the respective openings to secure the record disc on said turn table, said record discv being formed with a central hole, and sound grooves in the faces thereof, the innermost groove on `each face communicating with the hole in the 'disc for the purpose described. L

4. In combination, a phonograph turn table having a central depression formed in the top face thereof, a record disc formed with a series of spaced openings in the outer edge portion thereof, pins extending upwardly from the turn t-able for disposition within the respective openings to secure the disc on the turn table, the central portion of the disc being formed with an enlarged holeI adapted for registration with the central depression formed in theupper face of the turn table for the purpose described.

5. In a phonograph, the combination of acasing, a rotatable turn table, an electric motor for actuating the same, a record disc for disposition upon the turn table, and a throat, a tone arm swivelly mounted at its inner end on the throat, a reproduced unit carried by the outer end ofthe tone arm, an electric circuit for the motor, and a switch structure ara brush carried by the tone arm or engagel ment with the upper face of the insulating ring'and the contact st-rip.

. In testimon whereof I aiiix my signature.

RA DHIR SINGH KI-IAIRA. 

